Problem description:
Does every book have its own book number, or does all kinds of books have book numbers? Please answer me as soon as possible, I am in a hurry! Thank you!
Analysis:
Two-dimensional barcode technology-[default classification]
1. Background of 2D barcode technology
Since the appearance of one-dimensional bar code, it has attracted extensive attention and developed very rapidly. Its use has greatly improved the speed of data collection and information processing, improved work efficiency and made great contributions to the scientific and modern management.
Due to the limitation of information capacity, one-dimensional bar code is only the identification of "articles", not the description of "articles". Therefore, the use of one-dimensional barcode has to depend on the existence of database. In places where there is no database and it is not convenient to network, the use of one-dimensional bar code is greatly restricted, and sometimes it even becomes meaningless. In addition, it is very inconvenient and inefficient to use one-dimensional bar code to represent Chinese characters. With the development of modern high-tech, it is urgent to use bar codes to express more information in a limited geometric space to meet the ever-changing information expression needs. Two-dimensional code is produced to understand the problems that one-dimensional bar code can't solve. Because of its high density and high reliability, it can be used to represent data files (including Chinese character files), images and so on. Two-dimensional bar code is the most ideal method to store, carry and automatically read information, with large capacity and high reliability.
Second, the characteristics of two-dimensional bar code
high-density
At present, one-dimensional bar codes, such as EAN/UPC bar codes, which are more mature in application, are only used as identification data and cannot describe products because of their low density. If we want to know the product information, we must read the bar code and enter the database. This requires us to establish a database with bar code as the index field in advance. Two-dimensional bar code uses vertical dimension to improve the information density of bar code. Usually its density is dozens to hundreds of times that of one-dimensional bar code, so we can store all product information in a two-dimensional bar code. To view the commodity information, you only need to scan the two-dimensional bar code with reading equipment, without establishing a database in advance, and truly realize the description of "goods" with bar code.
With error correction function
The application of one-dimensional bar code is based on the fact that refusing to read (that is, not reading) is better than misreading (misreading). Therefore, one-dimensional bar codes are usually printed together with the information they represent. When the bar code is damaged (such as pollution, deinking, etc. ), you can use the keyboard to input without scanning the bar code. In view of the above principles, one-dimensional bar code does not consider the error correction function of bar code itself. Although the concept of check character is introduced, it is only limited to prevent reading errors. Two-dimensional bar codes can represent thousands of bytes of data. Usually, the information they represent cannot be printed together with bar code symbols. If there is no error correction function, when a part of the QR code is damaged, the barcode becomes meaningless, so the QR code introduces an error correction mechanism. This error correction mechanism enables the two-dimensional bar code to be read correctly when it is partially damaged due to perforation, fouling, etc. (see figure 1). The error correction algorithm of two-dimensional code is the same as that used by satellite and VCD. This error correction mechanism makes two-dimensional bar code a safe and reliable way of information storage and identification, which is incomparable to one-dimensional bar code.
Can represent many languages and characters.
Most one-dimensional bar codes can only represent 10 digits, 26 English letters and some special characters. The code l28 with the largest barcode character set can only represent 128 ASCII characters. Therefore, it is impossible to express other languages (such as Chinese characters and Japanese). ) with a one-dimensional barcode. Most two-dimensional bar codes have byte representation mode, which provides a mechanism to represent byte stream. We know that no matter what language or text is stored in a computer, it is expressed in the form of internal code, which is byte code. In this way, we can try to convert the information of various languages into a byte stream, and then use a two-dimensional bar code to represent this byte stream, thus providing an unprecedented way for bar code representation of various languages.
Representable image data
Because two-dimensional bar codes can represent byte data, and images are mostly stored in bytes, it is possible to represent images (such as photos, fingerprints, etc.). ) in the barcode.
An encryption mechanism can be introduced.
The introduction of encryption mechanism is another advantage of QR code. For example, when we use two-dimensional bar code to represent photos, we can first encrypt the image information with a certain encryption algorithm, and then use two-dimensional bar code to represent it. When identifying two-dimensional bar codes, a certain decryption algorithm can be applied to restore the represented photos. This can prevent the forgery of various certificates, cards, etc.
Third, the application scope of two-dimensional bar code
Two-dimensional barcodes can be used in the following aspects:
Documents: official documents, purchase orders, customs declarations and commercial documents;
License: passport, ID card, registration card, driver's license, membership card, ID card;
Warehouse inventory: goods inventory in logistics center and warehouse center;
Goods tracking: conference materials, production parts, customer service, mail order delivery, maintenance records, dangerous goods, logistics supply, ecological research;
Information confidentiality: commercial secrets, political information, military secrets and private letters.
Four, two-dimensional bar code and magnetic card, ic card, optical card comparison.
See table 1 for the comparison between QR code and other automatic identification technologies.
Table1:Comparison of 2D barcode with magnetic card, ic card and optical card
Comparison point
Two-dimensional bar code
magnetic card
smart card
Optical card
Antimagnetic force
strong
faint
medium
strong
be antistatic
strong
medium
medium
strong
Damage resistance
strong
knock-down
Perforable
Cutable
faint
launch
impervious
Noncutting
faint
launch
impervious
Noncutting
faint
launch
impervious
Noncutting
Photocopying ability
can
But I always don't
But I always don't
But I always don't
facsimile
can
But I always don't
But I always don't
But I always don't
capacity
1, 100 bytes
76 bytes
3kb
2mb
expense
1 yuan
10 yuan
300 yuan
500 yuan
The application prospect of verb (abbreviation of verb) two-dimensional bar code in China
As a new type of automatic identification technology, two-dimensional bar code has incomparable advantages over other automatic identification technologies, and has attracted the attention of bar code management departments and related departments in China since it came out. Since 1993, the research of two-dimensional bar code technology has been started in China Article Coding Center. China's first monograph on 2D barcode technology has been published. In order to comprehensively carry out the research on 2D barcode technology and open up the application pilot, the research and application pilot of 2D barcode technology in China Article Coding Center has been included in the "Ninth Five-Year Plan" key research project of the State Science and Technology Commission. This topic will carry out work from basic research, standard formulation, equipment development and pilot establishment, aiming at promoting the application process of QR code in China. In addition, many scientific research units, development companies, colleges and universities have also begun to develop the application of two-dimensional bar code technology. At present, many departments have the desire to use two-dimensional bar codes for personnel management and goods management. For example, the public security department wants to apply the QR code to the management of ID cards and mobile personnel, the entry-exit administration department wants to explore the application of the QR code to passports, and the customs also wants to try to use it in customs declarations. Some people have even started to use it. For example, two-dimensional barcode PDF4 17 has been applied to the tracking management of vehicle information in Shanghai Automobile Sales Center. According to the current situation, it is predicted that the application of QR code in China will develop greatly in five years.
Two-dimensional bar code will be widely used in personnel management in China at first.
With the progress of our society and science and technology, people's demand for modern personnel management is increasing day by day, which is the need to accurately describe the management object on the certificate. The automatic technology of QR code has great cost advantage and is easily accepted by various management departments. In the case that it is difficult to establish a comprehensive database of population management in China, the two-dimensional code on the portable ID card can contain all the identity information of people and also the photo information of people, so the popularization of this technology has more advantages than that of developed countries.
QR code will also have great development in logistics management.
Describing articles with two-dimensional bar codes is another aspect of the application of two-dimensional bar codes. It is necessary to describe the goods in storage and transportation. The present situation is mostly described in natural language, which greatly affects the speed and accuracy of information collection. Applying two-dimensional bar code to logistics, that is, making two-dimensional bar code on commodity packaging, is impossible for other automation technologies (such as ic cards). The application of two-dimensional barcode in logistics will accelerate the modernization of logistics management. Bar code bar code printer bar code printer bar code bar code.
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2005-03-24 06:38:59
Small knowledge of bar code ISBN [default classification]
A Chinese standard book number consists of an international standard book number (ISBN) and a book classification-classification number, in which ISBN is the main body of the Chinese standard book number and can be used independently.
Background of international standard book number
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As early as 65438+ Europe in the mid-1960s, the London School of Economics (lse.ac.uk/) and the British Publishers Association put forward the idea of establishing a clear international book number. In 1968, the International Organization for Standardization (ISO) adopted this proposal and immediately set up a working group to implement it. Finally, in June 1966 1 1, the third international conference on book market research and book trade rationalization in West Berlin formally reached an agreement.
Structure of international standard book number
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The ISBN consists of ten numbers and is divided into the following four parts:
Group 1: Group number: location code 0, 1: English 2: French 3: German 4: Japanese 5: Russian 7: Chinese.
The second group: the publishing house codes are distributed to various publishing houses by ISBN code distribution centers in various countries.
The third group: the book order code, given by the publishing house.
The fourth group: there is only one computer check code, from 0 to 10, 10 is replaced by X.
Group number: the group number is the code of a country, region, language or other organization group. It is designated by the international ISBN organization. China group number is a number "7".
Publishing house number: assigned by the national standard book number center, and its digits vary according to the number of books published by the applying publishing house.
Book serial number: The publishing house is responsible for the management and distribution. The digits L of the book serial number of various books published by various publishing houses are fixed, and the calculation formula is as follows: L=9- (digits of group number+digits of publishing house number)
Check code: the tenth digit of the Chinese Standard Book Number. Its value C 10 is calculated by the first nine digits of the China Standard Book Number (C 1-C9) weighted by the sum of 10-2, and the modulus of 1 1 is calculated as follows:
c 10 = 1 1-MOD(ci×( 1 1-I)， 1 1)
Where: modular congruence function. When the MOD function value is 1(C 10= 10), the check code is represented by x; When the MOD function value is 0 (C 10= 1 1), the check code is still represented by 0.
ISBN is used for printed matter, microfilm, educational television or movies, mixed media publications, microcomputer software, atlases and maps, Braille publications and electronic publications.
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2005-03-24 06:36:08
Advantages of Bar Code Technology-[Default Classification]
Bar code is by far the most economical and practical automatic identification technology. Bar code technology has the following advantages:
A. Fast input speed: Compared with keyboard input, bar code input speed is five times that of keyboard input, which can realize "instant data input".
B high reliability: the error rate of keyboard input data is 300%, the error rate of optical character recognition technology is110000, and the error rate of barcode technology is less than110000.
C. A large amount of information is collected: the traditional one-dimensional bar code can collect dozens of characters of information at a time, and the two-dimensional bar code can carry thousands of characters of information, and has certain automatic error correction ability.
D. Flexible and practical: Bar code identification can be used as a means of identification alone, can also be combined with related identification equipment to realize automatic identification, and can also be connected with other control equipment to realize automatic management.
In addition, the bar code label is simple to make, has no special requirements for equipment and materials, and the identification equipment is simple to operate without special training, and the equipment is relatively cheap.
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2005-03-24 06:35:36
Development History of Barcode-[Default Classification]
Bar code technology was first produced in the trembling twenties, and was born in the laboratory of Westinghouse. An eccentric inventor named John Kermode "whimsically" wants to realize the automatic sorting of postal documents. At that time, every idea about the application of electronic technology was very novel. His idea is to put a barcode on the envelope, and the information in the barcode is the address of the recipient, just like today's postal code. For this reason, Kermode invented the earliest bar code recognition. The design scheme is very simple, that is, one represents the number "1", two represents the number "2", and so on. Then, he invented a bar code reading device composed of basic components: scanner (which can emit light and receive reflected light); A method for measuring the band and space of reflected signal, namely edge positioning coil; And a method of using the measurement result, namely a decoder.
Kermode's scanner uses a newly invented photocell to collect reflected light. "Empty" reflects a strong signal, while "bar" reflects a weak signal. Unlike today's high-speed applications of electronic components, Kermode uses magnetic coils to measure "bars" and "spaces". Just like a child connecting a wire to a battery and winding it around a nail to clamp paper. Kermode uses a coil with an iron core to attract a switch when receiving the "empty" signal, and release the switch when receiving the "bar" signal to connect the circuit. So the earliest bar code readers were very noisy. The switch is controlled by a series of relays, and the "on" and "off" are determined by the number of "paper strips" printed on the envelope. In this way, the bar code symbol directly sorts the letters.
Shortly thereafter, Douglas Young, a collaborator of Kermode, made some improvements on the basis of Kermode code. Kermode code contains very little information, so it is difficult to compile more than ten different codes. Young codes use fewer bars, but the size of the space between bars changes, just as UPC barcode symbols today use four different bar sizes. The new bar code symbol can encode one hundred different regions in the same size space, while Kermode code can only encode ten different regions.
It was not until 1949 that the omni-directional bar code symbols invented by Noam Woodland and Bernard Silver were recorded for the first time. Prior to this, there was no record of bar code technology in patent literature, and there was no precedent for practical application. Noam Woodland and Bemmad Silver's idea is to use Kermode and Yang's vertical "strips" and "spaces" to bend them into a ring, much like the target of archery. In this way, the scanner can decode the bar code symbol by scanning the center of the graph, regardless of the direction of the bar code symbol.
In the process of constantly improving this patented technology, the science fiction writer Isaac-Azimov described an example of automatic identification using a new information coding method in his book * * *(The Sun of * * *). At that time, people thought that the barcode symbol in this book looked like Fang Gezi's chessboard, but today's barcode professionals will immediately realize that it is a two-dimensional matrix barcode symbol. Although this bar code symbol has no direction, no positioning and no timing, it is obvious that it represents a digital code with high information density.
It was not until 1970 that Iterface Mechani *** s developed the "two-dimensional code" that the printing and reading equipment of two-dimensional matrix bar code came out at a price suitable for sale. At that time, two-dimensional matrix bar code was used to realize the automation of newspaper typesetting process. Two-dimensional matrix bar code is printed on paper tape and scanned and read by today's one-dimensional CCD scanner. The light emitted by CCD shines on the paper tape, and each photocell is aimed at different areas of the paper tape. Each photovoltaic cell outputs different patterns according to whether the bar code is printed on paper tape or not, and combines them to generate high-density information patterns. In this way, a single character can be printed in the same size space as a single bar in the early Kermode code. Timing information is also included, so the whole process is reasonable. When the first system entered the market, the price of the whole set of equipment including printing and reading equipment was about $5,000.
Shortly thereafter, with the continuous development of LED (light emitting diode), microprocessor and laser diode, a new symbol (symbolism) and its explosion came, which was called "barcode industry". Today, it is difficult to find companies or individuals who have not been directly exposed to fast and accurate barcode technology. With the rapid technological progress and development in this field, more and more application fields are developed every day. Before long, bar codes will be as popular as light bulbs and transistor radios, which will make everyone's life easier and more convenient.
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2005-03-24 06:34:49
Understanding Barcodes-[Default Classification]
Bar code is a set of bars and empty symbols arranged according to certain coding rules, which is used to represent information composed of certain characters, numbers and symbols. Bar code system is an automatic identification system composed of bar code symbol design, production and scanning reading.
Introduction of bar code coding mode (code system);
There are many kinds of bar codes, and there are about twenty common coding systems, including:
Code39 (standard code 39), Codabar code (Kudbar code), Code25 (standard code 25), ITF25 code (cross code 25), Matrix code 25 (matrix code 25), UPC-A code, UPC-E code, EAN- 13 code (EAN- 13 code). China postal code (variant of Matrix 25 code), Code-B code, MSI code, Code 1 1 code, Code93 code, ISBN code, ISSN code, Code 128 code (Code 128 code, including ean/kloc-0).
At present, EAN code and UPC code are widely used in the world to uniquely identify a commodity in the world. This is the most common bar code in supermarkets), Code39 (which can represent numbers and letters and is most widely used in management field), ITF25 (which is most widely used in logistics management field), Codebar (mostly used in medical and book fields), Code93, Code 128, etc. Among them, EAN code is a commodity bar code widely used in the world today, which has become the basis of electronic data interchange (EDI). UPC code is mainly used in the United States and Canada; In various bar code application systems, Code39 can be composed of numbers and letters * * *, so it is widely used in the internal management of various industries. Codebar code is also widely used in blood banks, libraries and photo studios.
In addition to the one-dimensional bar codes listed above, two-dimensional bar codes have also developed rapidly and been applied in many fields.
Introduction to common bar codes:
EAN code:
EAN code is a kind of commodity bar code formulated by ean international organization, which is used all over the world. There are two kinds of EAN code symbols: the standard version (EAN- 13) and the abbreviated version (EAN-8), and the common commodity bar codes in China are equivalent to them. The bar code printed on the packaging of the goods we buy every day is generally EAN code.
UPC code:
UPC code is a commodity bar code formulated by the United States Uniform Coding Committee, which is mainly used in the United States and Canada, and we can see it on the goods imported from the United States.
Size 39:
Code 39 is a bar code, which can represent numbers, letters and other information. It is mainly used for the automatic management of industry, books and tickets, and is widely used at present.
Bar code:
Kudba code can also represent numeric and alphabetic information, which is mainly used for automatic identification in medical and health care, library and information, materials and other fields.
Two-dimensional barcode:
One-dimensional bar codes carry limited information. For example, the barcode on a commodity can only hold 13 digits (EAN- 13 code) * *, and more information can only be supported by the commodity database. If there is no pre-established database, such bar code is meaningless, thus limiting the application scope of bar code to some extent. Because of this, two-dimensional bar code was invented in the 1990s. In addition to the advantages of one-dimensional bar code, two-dimensional bar code also has the advantages of large amount of information, high reliability, strong confidentiality and strong anti-counterfeiting.
At present, two-dimensional bar codes mainly include PDF4 17 code, Code49 code, Code 16K code, Data Matrix code, MaxiCode code code and so on. , mainly divided into stacked or layered codes and chessboard or matrix codes.
As a new information storage and transmission technology, two-dimensional bar code has been widely concerned by the international community since its birth. After several years of efforts, it has been applied in many fields such as national defense, public security, transportation, medical care, industry, commerce, finance, customs and * * * management.
With its huge information carrying capacity, two-dimensional bar code can include the information stored in the background database when using one-dimensional bar code in the past, and the corresponding information can be obtained directly by reading the bar code. Moreover, the QR code also has error correction technology and anti-counterfeiting function, which increases the security of data.
Two-dimensional bar code can be used to compile photos and fingerprints, which can effectively solve the problems of machine-readable and anti-counterfeiting of documents. Therefore, it can be widely used in passports, identity cards, driver's licenses, military officers' cards, health certificates, insurance cards and so on.
PDF4 17 technology has been used in driver's licenses, US military licenses and military medical licenses in more than ten states, such as Arizona, USA, several years ago. Personal information and photos on certificates are encoded in two-dimensional bar codes, which can not only realize automatic reading of identity cards, but also effectively prevent the occurrence of forged certificates. Many countries, such as the Philippines, Egypt, Bahrain and so on. The ID card or driver's license also adopts the two-dimensional bar code technology, and the passport of the China Special Administrative Region also adopts the two-dimensional bar code technology.
In addition, in customs declarations, long-distance freight bills, tax bills and insurance registration forms, there are also examples of using QR code technology to solve data input and prevent forgery and deletion of forms.
Two-dimensional code has also been initially applied in some domestic fields, such as certified public accountant certificate, automobile sales, after-sales service and so on.
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2005-03-24 06:33:20
Understand the basic principle of barcode-[default classification]
It may be easy for a professional to give up the superficial and useless bar code education. I can agree that a little knowledge is a dangerous thing. However, for any science, students always have to learn from one point: this truth is correct everywhere. Nowadays, many courses about fundamentally different contents, such as production engineering and retail market, include the content of bar code. Using barcode technology to collect effective information supports many aspects of industry and commerce.
Many years ago, I led a group of students to a famous supermarket to visit the electronic vending system equipped with bar code scanning equipment, and wanted to know how much work this system could accomplish.
This visit did not achieve the purpose of demonstrating the success of this electronic sales system. Everything will go wrong. The market uses EAN 13 code, which is a frequent problem. It uses a poor quality computer printer, and the bar code is printed on a small label, which is attached to the goods by people who have no experience in using bar codes. Many labels are either attached to curved surfaces or to packages without supporting surfaces. Like potted plants. To make matters worse, they use a contact pen scanner. When the bar code can't be scanned and read (which often happens), the cashier will enter these thirteen numbers with the keyboard.
Unfortunately, a good idea has no good result. To sum up, there are the following problems:
Wrong barcode label type is used.
The label is not pasted correctly.
The scanner is the wrong type.
The barcode type selected for this application is incorrect.
It is gratifying that this bad situation does not happen often now, but it is more important to teach the basic principles of bar code making and using correctly. More and more large companies regard barcode data acquisition technology as the basis of the pyramid of electronic trading system. Furthermore, due to the decline in the price of bar code system, bar code scanning technology has also been brought into the field of many small enterprises.
Problems in the computer are gradually appearing in the bar code system. With the decline of hardware and software prices and the expansion of the market, users without technical background are more likely to assemble bar code systems themselves. For example, the price of fixed laser scanners has dropped by nearly ten times in ten years, and most bar code software is sold with scanners.
This increase in do-it-yourself opportunities has its own factors to create unfortunate events, unless the basic principle of information collection using bar codes is understood by users and applied to specific environments.
What is the basic principle of bar code?
Determine what the information collection requirements of the bar code system are, and determine the exceptions relative to the general law.
Determine which barcode is suitable for this information gathering environment.
Understand the problems and opportunities of labeling items to be scanned.
Understand the problems and opportunities when scanning items that need to be recorded.
Before asking questions, find out what advice you can get from a professional company.
Remember, if you can't scan items, your investment is a waste.
The whole bar code system must be specially designed, and the opportunity of information collection and the problem of using bar code technology must be checked. When determining the main factors, they should not be separated, but should be regarded as interactive and influential parts, just like the above example.
First, the bar code
Some people foolishly think that bar codes are just the arrangement of bars and spaces with different widths, which is of course wrong. The simplicity of bar code arrangement is also its strength. Behind the development of bar code lies the hard work of designers. Like all user interfaces and automatic data collection systems, these experiences should not be displayed to confuse users, but must be understood by designers.
It must be emphasized that all barcodes are designed for special environments and applications. For example, barcodes used on large transport containers are quite different from those used on small packages or retail goods.
Second, the printing and pasting of bar codes.
For example, EAN code is designed for high quality printing, which is ideal for commodity packaging printing. If a low-grade printing method is adopted, it may be more appropriate not to choose another bar code, such as a combination of a shorter bar code and a computer with internal database query function.
Bar code professional companies have introduced a large number of hardware and software to meet all the needs of bar code printing. The types, specifications and prices of bar code labels are all factors to be considered. Sticking the barcode label on the item to be confirmed is another important factor. It's no use labeling the wrong items.
Scanning factors, including product type (size, weight, etc.). ), the size and direction of the tag, the relative motion between the tag and the scanner, and the scanning speed must all be considered. The cost of labeling items must be clear. The retail mall is a good example, which shows that the use of bar code labels on goods makes it possible to collect data in real time at low cost.
Educational principles
Some basic bar code technology must be taught, although the depth and breadth of these basic principles may vary with students and courses. It must be emphasized that each part should be explained in the whole application, rather than discussing one part separately. Bar code education should be based on the following aspects:
optical scan
The principle that a light source reflects from a surface applies to all bar code systems. Understanding the reflection effect of different surfaces and different light sources is related to the success or failure of application. (For example, bar codes rely on very accurate distinction between bars and spaces).
Bar code design
Barcode has a wide range of choices, from simple but efficient intermediate code 25 to EAN 13 code and then to overlapping code. It should be emphasized that the ability and application scope of bar codes are basically different. (For example, the symbol arrangement of many bar codes is limited, but other bar codes include the function of letter arrangement).
Factors to be considered in selecting bar code
Bar code printing and label pasting.
The size and spacing of labels (for example, retail packaging will use simple bar codes such as EAN8 code for aesthetics).
The principle of scanning is different from the operation of different scanners (for example, bar codes are recognized in different ways, including pulse recognition and image recognition).
conclusion
The use of bar codes provides people with a good chance of success, and there is also a great possibility of mistakes when asking. There is no simple conclusion that can help people successfully use barcode technology. If we want to ensure the increasing application of this most efficient technology, firstly, we should educate the basic principles of barcode, and secondly, we should conduct extensive practical education, and professionals should provide suggestions to avoid possible mistakes.